You can dimensionalize most measure expressions by using the aggr() function

Aggr( <YourMeasureExpression> , Dimension1, Dimension2, etc...)

...where Dimension1 etc... determines the level of aggregation which you need to be explicit about.

Also - there is probably a data model solution to this question as well. You can create a resident load to create a new table that leverages qlik's row level association to buckets dates into the 1 or more of the 3 date ranges. Then there is less calculation in the UI. Could be an option if you run into slowness in chart rendering.